As someone with an investment of time and understanding in Windows Phone it's definitely a good thing. What it comes to mean in time as the finer details are announced and the implementations of those details are worked out we shall but see.
This is definitely an investment in the future and it will be a while before we see any actual devices because of todays announcement. But, by the end of 2012 there will be millions of people around the world with smartphones running a Windows Phone 7 (or maybe 8?) operating system.
The biggest change I can predict that will affect me in the short term is that Nokia will have a big influence on chassis specs and what was expected for chassis-2, later this year, won't happen and we'll ultimately end up with more than 2 chassis specs for WP7. Amd maybe even more for WP8?
I expect Symbian to still be around for a very long time.
I don't expect today's announcements to have any short term impact on tablet plans for either company. - For the record I don't want to see WP7 running on a tablet/slate. I don't think it would work. I do think that something else based on the Metro theme could work really well though but it would need to be designed/targeted appropriately/specifically for such a device. (phone != tablet != pc)
3 big questions I have right now though:
- Will Nokia give up on the Ovi store? or will it be merged with the marketplace-somehow?
- What does this mean for the other WP7 device manufacturers? Will some of them leave the platform? What about the ones who have yet to release devices? (Micorosoft announced 10 OEM partners when they launched the platform at WMC last year.)
- What do Blackberry (& WebOS - if there are any) developers think of this? and the seemingly widely held belief that there is now a three horse race?
And a bonus 4th - when can I have a device? ;)
For those that have missed them:
The Microsoft press release
The Nokia press release